Lubricant injector



Patented May 5, 1953 UNITED STATES PATENT OFF LUBRICTIECTOR Alexander?.Fox; University City, and Gar-l B'.

Mueller, St. Ilouis, Mo., assienors` to Lincoln Engineering Company, StrLouis, Moz.,` a corpo-V ration of Missouri Application April- 2'2,195`0`, SeralNo. 157,562

(Cl. 18d-JY is the' provision oi an improved simplified in'- jec'torl oithis type'.

general, an injector' of this' invention cor'npri'se's an injector bodyhaving av lubricant discharge chamber which opens `at one end intol anenlarged opening', with an annular shoulder at theA inner end of theopening. A; special check valve is provided inthis opening. This checkvalve, according to the invention, consists of a one-piece body moldedof soft, resilient' mate'- rial having a base seated against theshoulder and al nipple projecting outward-lv ironithe center of thehase, with an opening' or passage throughthc base into thel nipple, therlatter heing transversely slit toprovidev a port through the nipple fromthe opening or passage. The valve is held in the opening by means whichcompresses the base of the val-'veY againstl the shoulder to provide a'seal. A plunger is re"- ciprofcahl'le in the discharge chamber and' isinovahle through a' pressure stroke' to discharge lubricant from thedischarge chamber through the valve. The passagethrough the hase of' thevalve of smaller cross-section than the working end oi the plnnger sothat the hase4 of' the valve' presents a seat at said one end of thedischarge' chain-loer for cushioned sealing engage# inenthy the Workingend of the plunger `at the enelE of its pressi-ire stroke. With this:arrange'- ment, the valve has at least three fonctions in addition. t'oits function as a check valve: ci) It provides its own seal; (2l itVacts as e; cushion receiving theirnpact of the pion-ger `when theplunger is* driven through a pressure stroke and (3) the base of thevalve is' utilized as' a valve seat for engagement hy the working' enoof the plunger to seal against leakage of lubricant past the plunger andoutV through the check valve. Other features will be in part' apparentand 4in part pointed ont hereinafter.

The invention accordingly comprises' the elerrients, features ofconstruction, and' arrange'- rnents oi parts which will he ereinplincdin the structures hereinafter described, and the scope of thelapplication of which will he' indicated' in the following claims'.

In the accompanying drawing, in which one of various possibleembodiments of the .invention is illustrated,

ses

Fig. 1 is a View in elevation ci an injector of this invention mountedin a manifold, the latter losing" shownin section;

Fig. 2J is a full vertical section taken on line 2:-2- of Fie. 1;

Fig; 32 is an elevation of ache'clr valve ner seof the injector; and

rig; Il is a horizontal section taken online- 4;--4 of lis.V

Similar reference` characters indicatecorre'- spcncling parts throughoutthe several views of 'the dra-wing:

Referring' to the drawing', an injector of this invention is shown tocomprise' an injector body l? formed to provide al firstl cylinder' 3-and a' seoo-nd cylinder 5 at right angles to one another. As hereinillustrated; the body l is made one piece in the form of a T, the headof the 1' being the first cylinder 3 andi thel stem of the T being thesecond cylinder 5r.4 The cylinder 3 has a bore l and enlarged open-ings9 and l l at. its-upper and lower ends asi viewed Fig. 2..A Thesemrnaybe readily provided by boring through the "head of the` 'l' andcourlterhoring its ends'. The` cylinder 5 has a bore i3 which. entends.fromits outer end toward het terminates short et the here 'I- ofcylinder 31 so as to provide a shoulder t5: at the inner end ci thecylinder 5f A. smaller' here l'l aty the inner end oi. thecylinder 5forms rai-transsfer port estalolishing` communication between thecylinders 3 and; 5:.

A plonger la has e; sliding' nt'. at its upper end iiiV the here L Thisbore: constitutes the dis charge chamber of the injector and will beyhereinafterreie'rienf to as such. "I'h'ef plongerr extends down from thedischargel charnlher t through the open-ing' lll and is contained l'oy aiitti-ng 2| threaded in the open-ing Il. The fitting 211 has a chamber23`l which is' open at its upper' end. This charnher '2'3 constitutesthe inlet cha-miler of theY injector and receives the plunger t9. Thechamber 23' isf largo enoughtoaccommodatea helical compression spring2'5 surrounding' the plonger and reacting from theI shoulder 21 at theupper end ofthe opening H against a collar' 29 on thep'lnnger adjacentits lower end. The spring 2'5 biases the plunger` downward to karetracted position determined by the engagement of the lower end ci theplunger with the 'bottom ci the chamber 23, The plunger has an axialpassage 3v from its lower end up' to a cross'- passage 3i' adjacent itsupper end leading to a peripheral groove 33. `The plunger is adapted to:nove upward to a position wherein the groove 33 registers with thetransfer port r1.

The fitting 2| has a hexagonal head 35 and a. reduced-diameter stud 31extending down at its lower end. It is adapted for mounting in alubricant manifold 39 in the manner illustrated in Figs. 1 and 2. Asshown, the manifold consists f a block having a vertical opening 4Ireceiving the lower portion of the fitting below the head 35, a cap nut43 being threaded on the stud 31 in the lower end of the opening 4I tohold the injector in sealed assembled relation with the manifold. Themanifold has a longitudinal lubricant passage 45 and is supplied withlubricant from a source of supply through a lubricant supply line 41.The manifold, which is fragmentarily shown in Fig. l, is of a typeadapted to receive a plurality of injectors side-by-side, and issupported by a bracket 49. In the fitting 2| below its head is an inletport 5| providing for communication between the manifold and the chamber23.

The plunger I9 is adapted to move upward through a pressure stroke to alimiting position determined by engagement of its upper or working endwith a special check valve member 53, which constitutes an importantfeature of this invention. As shown, the check valve member 53 consistsof a one-piece molded body, of rubber or the like, and preferably an oiland grease resistant synthetic rubber such as Hycar, a butadienecopolymer with acrylonitrile, having a flat base 55 with a nipple 51projecting from the upper face of the base in the direction of flow oflubricant. The valve is formed with an opening or passage 59 through thebase into the nipple, the latter being transversely slit as indicated at6| where it joins the base over part of its periphery (about as shown inFigs. 3 and 4), to provide a port through the nipple from the opening orpassage 59. As herein illustrated, the base of the valve is in the formof a disc of such diameter as to t in the upper opening 9 of theinjector body I. The passage 59 is of smaller cross-section than theworking end of the plunger I9.

The valve 53 is fitted in the opening 9 with its base engaged againstthe flat shoulder 63 at the bottom of the opening 9 and with the nipple51 projecting upward. The valve is retained in the opening by a gland 65threaded in the opening and compressing the base of the Valve againstthe shoulder 63 to provide a seal. The gland has an axial passage 61receiving the nipple. This passage is the outlet of the injector and isadapted to have a lubricant line 69 connected into it by a fitting 1D.

A piston 1I, consisting of a disc of rubber, preferably an oil andgrease resistant synthetic rubber such as above mentioned, is slidablein the cylinder 5. This piston is backed by a follower 13 which consistsof a hollow cylinder slidable in the lcylinder 5, closed at its innerend engaged with the piston 1I and open at its outer end. The cylinder 5is externally provided with a raised screw thread 15 which terminatesshort of the cylinder 3 so as to provide an annular groove 11 betweenthe inner end of the thread 15 and the cylinder 3. Adjustably threadedon the thread 15 is a cap 19. After the cap is threaded on, an inwardlydirected flange 8l is formed at its inner end Which reaches into thegroove 11 to prevent removal of the cap while allowing for its axialadjustment between the solid and dotted line positions shown in Fig. 2.At 83 is shown a stem having a head 85 backing the closed end of thecylindrical follower 13. The stem extends out of the follower andthrough an opening 81 in the head of the cap 19. The opening 81 issmaller than the diameter of the follower 13. A helical compressionspring 89 surrounding the stem reacts from the head of the cap againstthe head on the stem to bias the stem, follower 13 and piston 1| towardthe cylinder 3.

Operation of the above-described injector is as follows:

The cap 19 is adjusted to a position such as illustrated in solid linesin Fig, 2. With the cap in such position, the piston 1I, follower 13 andstem 83 can move to the right (as viewed in Fig. 2) until the outer endof the follower 13 engages the inside of the head of the cap 19. Fig. 2illustrates the parts in the positions they occupy when the lubricantsupply line 41, manifold 39 and injector inlet chamber 23 are vented torelieve the pressure of lubricant in the lubricating system. Under thesecircumstances, the plunger I9 is in its lower retracted position andpiston 1I is in its forward advanced position engaging the shoulder I5.Assuming that the injector has been primed and previously cycled, therewill be a measured charge Iof lubricant in the discharge chamber abovethe upper end of the plunger I9.

Upon development of pressure in the lubricant supply line, the manifoldand the injector inlet chamber 23, the plunger I9 is subjected to forcetending to raise it against the bias of spring 25. When this forcereaches injector-cycling value (600 to 1000 p. s, i., for example) theplunger I9 is driven upward until its upper end engages the bottom ofthe valve 53. The latter acts as a cushion for the impact. This forcesthe charge of lubricant from the chamber 1 through the passage 59 andslit 6I in the check valve 53 and out through the line 69. It alsobrings the annular groove 33 into registry with the transfer port I1.Lubricant thereupon flows from the chamber 23 through the axial passage3|] in the plunger and through the cross-passage or radial port 3 intothe groove 33 and through the trans- Ier port I1 into the cylinder 5,forcing the piston 1I back until the follower 13 engages the inside ofthe head of the cap 19. Thus, the cylinder 5 receives a charge oflubricant, the amount of the charge depending upon the displacement ofthe piston 1I, which is in turn dependent upon the position of the cap19. Stem 83 protrudes from the cap 1S and acts as a telltale to apprisethe operator that the injector has cycled. It will be here understoodthat by varying the adjustment of the cap, the injector may be set toinject different measured charges of lubricant. It will be seen that thecylinder 5 serves as a measuring chamber and may be referred to as such.

When the plunger I9 is driven upward to the upper limit of its stroke bypressure in chamber 23, its upper end comes into sealing engagement withthe bottom seat portion of the valve 53 presented at the upper end ofthe discharge chamber 1, the plunger being held by the pressure tendingto drive the plunger upward. Thus, when the plunger is driven upward tothe end of its pressure stroke it seals the passage 59 in the valve 53and thus prevents escape through passage 59 of any lubricant that mayleak upward past the plunger. As shown in Fig. 2, the upper end of theplunger may be made convex to insure this sealing action. This isimportant, particularly where the injector is to deliver relativelysmall measured charges, because without such a seal, should lubricantleak past the plunger there would be a more or less continuous ow oflubricant from the injector during the interval in whichinjector-cycling pressure is developed in the chamber 23. With thearrangement wherein the upper end of the plunger engages the resilientvalve 93, the injector maintains close control over the amount oflubricant injected, even though the plunger I9 is allowed ampletolerance for readily sliding in the bore 1.

Upon subsequent relief of pressure in the lubricant supply line lil',manifold 39, and injector inlet chamber 29, the spring 25 drives theplunger I9 down to its retracted position illustrated in Fig. 2. Spring89 thereupon acts to drive the piston 1| to its forward position againstshoulder I5, thus forcing the measured charge of lubricant from thecylinderpr measuring chamber 5 into the discharge chamber 'I above theupper end of the plunger I9. The injector is thus re-charged and re-setfor the next cycle.

It will be noted that in the retracted position of the plunger I9, itsupper end face is just clear of the transfer port l1 and its annularperipheral groove 33 is just below the shoulder 21 at the lower end ofthe bore or discharge chamber l'. As the plunger moves upward, itcrosses and blocks the transfer port I 'i and forces the charge in thedischarge chamber' 'l out through the check valve 53. The latter opensunder pressure in its passage 59 by bending of the nipple 51 to open upthe slit 6I. It closes by back pressure in the outlet forcing the nippletoward the base 55 to close the slit. It is important that in theadvanced posiion of the plunger at the end of a pressure stroke, thegroove 33 registers with the transfer port. The upward movement of theplunger is limited by the engagement of its upper end with the bottom ofthe valve 53 and, accordingly, the groove 33 is spaced from the upperend of the plunger a distance corresponding to the spacing of the bottomof the valve and the port I1.

The injector of this invention, as will be seen from the drawing andtheabove description, is an improvement upon prior injectors of the sameclass in being small, compact and rugged, of simpliied construction andeasily installed. The use of the simple check valve 53 is a feature ofconsiderable importance as this valve is in itself simple and economicalto manufacture, which is easily installed and replaced when necessary,which provides its own packing, and which also acts both as a valve seatand as a cushion for the plunger.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As many changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

We claim:

1. In a lubricant injector. an injector body having a discharge chamberopening at one end into an enlarged outlet opening, with an outwardlyfacing shoulder at the inner end of the outlet opening, a check valve inthe outlet opening comprising a one-piece body of soft resilientmaterial having a base seated on the shoulder and a nipple projectingfrom the outer face of the base, the valve having a passage through thebase into the nipple and the latter being transversely slit over part ofits periphery to provide a port through the nipple from the passage,means holding the base 0f the valve against the shoulder, and a plungerreciprocable in the discharge chamber and movable through a pressurestroke to discharge lubricant from the discharge chamber through thevalve, the passage through the base of the valve being of smallercross-section than the working end of the plunger so that the base ofthe valve presents a seat at said one end of the discharge chamber forcushioned sealing engagement by the working end of the plunger at theend of its pressure stroke.

2. In a lubricant injector, an injector body having a discharge chamberopening at one end into an enlarged cylindrical outlet opening, with anoutwardly facing annular shoulder at the inner end of the outletopening, a check valve in the outlet opening comprising a one-piecemolded body of elastomeric material having a disc portion seated on theshoulder and a nipple projecting centrally from the outer face of thedisc portion, the valve having a passage through the disc portion intothe nipple, the nipple being transversely slit where it joins the discportion over part of its periphery to provide a port through the nipplefrom the passage, a gland threaded in the outlet opening marginallycompressing the disc portion against the shoulder, and a plungerreciprocable in the discharge chamber and movable toward the valvethrough a pressure stroke to discharge lubricant from the dischargechamber through the valve, the passage through the disc portion being ofsmaller cross-section than the working end of the plunger so that thedisc portion presents a seat at said one end of the discharge chamberfor cushioned sealing engagement by the working end of the plunger atthe end of its pressure stroke.

ALEXANDER P. FOX. CARL H. MUELLER.

References Cited in the le 0f this patent UNITED STATES PATENTS NumberName Date 1,942,096 Hallerberg Jan. 2, 1934 1,988,152 Battle Jan. 15,1935 2,296,861 Matter Sept. 29, 1942 2,448,583 Fox Sept. '7, 1948

